From 55f49f26821f379c451deb9fd6de8e59afb9b37e Mon Sep 17 00:00:00 2001 From: Nathaniel McCallum Date: Wed, 18 Nov 2009 20:15:28 -0500 Subject: [PATCH] USB: handle bcd incrementation in usb modalias generation This patch fixes a bug when incrementing/decrementing on a BCD formatted integer (i.e. 0x09++ should be 0x10 not 0x0A). It just adds a function for incrementing/decrementing BCD integers by converting to decimal, doing the increment/decrement and then converting back to BCD. Signed-off-by: Nathaniel McCallum Signed-off-by: Greg Kroah-Hartman --- scripts/mod/file2alias.c | 49 ++++++++++++++++++++++++++++++++++++++-- 1 file changed, 47 insertions(+), 2 deletions(-) diff --git a/scripts/mod/file2alias.c b/scripts/mod/file2alias.c index e31f03aaf294..6f426afbc522 100644 --- a/scripts/mod/file2alias.c +++ b/scripts/mod/file2alias.c @@ -160,6 +160,45 @@ static void do_usb_entry(struct usb_device_id *id, "MODULE_ALIAS(\"%s\");\n", alias); } +/* Handles increment/decrement of BCD formatted integers */ +/* Returns the previous value, so it works like i++ or i-- */ +static unsigned int incbcd(unsigned int *bcd, + int inc, + unsigned char max, + size_t chars) +{ + unsigned int init = *bcd, i, j; + unsigned long long c, dec = 0; + + /* If bcd is not in BCD format, just increment */ + if (max > 0x9) { + *bcd += inc; + return init; + } + + /* Convert BCD to Decimal */ + for (i=0 ; i < chars ; i++) { + c = (*bcd >> (i << 2)) & 0xf; + c = c > 9 ? 9 : c; /* force to bcd just in case */ + for (j=0 ; j < i ; j++) + c = c * 10; + dec += c; + } + + /* Do our increment/decrement */ + dec += inc; + *bcd = 0; + + /* Convert back to BCD */ + for (i=0 ; i < chars ; i++) { + for (c=1,j=0 ; j < i ; j++) + c = c * 10; + c = (dec / c) % 10; + *bcd += c << (i << 2); + } + return init; +} + static void do_usb_entry_multi(struct usb_device_id *id, struct module *mod) { unsigned int devlo, devhi; @@ -208,10 +247,16 @@ static void do_usb_entry_multi(struct usb_device_id *id, struct module *mod) } if (clo > 0x0) - do_usb_entry(id, devlo++, ndigits, clo, max, max, mod); + do_usb_entry(id, + incbcd(&devlo, 1, max, + sizeof(id->bcdDevice_lo) * 2), + ndigits, clo, max, max, mod); if (chi < max) - do_usb_entry(id, devhi--, ndigits, 0x0, chi, max, mod); + do_usb_entry(id, + incbcd(&devhi, -1, max, + sizeof(id->bcdDevice_lo) * 2), + ndigits, 0x0, chi, max, mod); } } -- 2.20.1